1. The Field of the Invention
The present invention is directed generally to methods and apparatus for stabilizing a surgical site and more specifically to methods and apparatus for isolating and immobilizing a surgical site during cardiac surgical procedures.
2. Related Application
Benefit of the earlier filing date of Provisional Patent application Ser. No. 60/034,888, filed Jan. 31, 1997, is claimed for this application under Section 119(e) of Title 35 of the United States Code.
3. The Relevant Technology
Throughout many surgical procedures, and especially surgical procedures involving the heart, anatomical and physiological constraints often impede the surgical process. For example, in cardiac surgical procedures, the requisite surgical site is often difficult to access and manage. Anatomically, the heart is well protected by the sternum, the rib cage, and multiple layers of connective tissues, and thus often necessitates arduous dissection. Physiologically, a beating heart presents anything but a stable surgical field. As a result, procedures such as coronary artery bypass on a beating heart demonstrate distinct surgical barriers.
Coronary artery bypass surgery is commonly required when coronary arteries narrowed by cholesterol-rich fatty deposits or plaque are unable to supply the heart muscle with a sufficient amount of blood, and as a result, the heart becomes starved for oxygen. Left untreated, coronary artery disease ultimately leads to acute myocardial infarction, or heart attack. In coronary artery bypass surgery, a surgeon grafts a section of a healthy vessel to bypass a stenotic or partially blocked portion of a coronary artery in order to ameliorate the oxygen supply to the heart muscle.
In many cases, coronary bypass surgery may be performed on a beating heart. This eliminates some of the risks, such as ischemic damage to the heart or peripheral tissues, and exposure of the blood to extracorporeal circulation, tubing, filters and oxygenators associated with procedures wherein the heart is stopped. However, in coronary bypass on a beating heart, surgeons have traditionally encountered difficulty isolating and immobilizing the diseased coronary arteries. Essentially, every beat of the heart results in movement at the site of the bypass which disrupts the surgery and may even damage the bypass graft.
In order to secure the surgical site, surgeons have conventionally performed tamponade, or compression of the heart, by utilizing devices that press down on the tissue at the surgical site. Yet such an approach lacks precise isolation of the coronary artery and diminishes access thereto. Alternatively, surgeons have utilized a pair of suction devices to pull the tissue surrounding and including a coronary artery slightly away from the heart. This approach offers tenuous stability and isolation of the surgical site at best.